Technical Field
The present invention concerns a pole shoe, in particular a pole shoe of a generator.
Description of the Related Art
A pole shoe is a component that includes a material of high permeability such as for example iron. The pole shoe serves to cause the magnetic field lines of a permanent magnet or a winding to issue in a defined form, and to distribute same. By way of example in an electric motor the magnetic exciter field is distributed to the armature in the form of a segment of a circle by a pole shoe. That homogenizes the variation in the flux density along the revolution of the armature. In that case not only can the stator have pole shoes, but also the armature of dc motors or the rotor (rotor member) of turbo generators. The pole shoes of electrically excited ac/three-phase machines as well as the armature of dc motors are in that case generally of a laminate nature to avoid eddy current losses.
Wind power installations involve the use of three-phase asynchronous generators or three-phase synchronous generators which respectively have pole shoes in the rotor or stator. Because of the increasing size of the generators of wind power installations and the increasing loading that this entails the known configurations of pole shoes are encountering their load limits from mechanical and thermal points of view.